title: Actions of the opioid antagonist, nalmefene, and congeners on reperfusion cardiac arrhythmias and regional left coronary blood flow.
abstract: Opioid antagonists have been shown to prevent the occurrence of lethal arrhythmias following coronary reperfusion. In this study, we have examined the effect of a new, long-lasting, potent opioid antagonist, nalmefene, and congeners in the prevention of reperfusion arrhythmias in dogs. Nalmefene given at a dose of 1 mg/kg i.v. reduced the incidence of reperfusion arrhythmias significantly when compared to the saline control. Neither N-methyl nalmefene, a quaternary analog that does not cross the blood brain barrier, nor (+) nalmefene, an isomer with no anti-opioid actions, provided any protection against reperfusion arrhythmias. Regional myocardial blood flow profiles, during and after coronary occlusion, were not different between the nalmefene- and saline-treated groups. We conclude that nalmefene prevents the occurrence of reperfusion-induced arrhythmias by blocking opioid receptors in the brain.
authors.affiliation: Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta.
authors.forename: R W
authors.initials: RW
authors.lastname: Caldwell
authors.forename: R
authors.initials: R
authors.lastname: Nagarajan
authors.forename: A
authors.initials: A
authors.lastname: Chryssanthis
authors.forename: R R
authors.initials: RR
authors.lastname: Tuttle
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000517:prevention & control*; D003326:Coronary Circulation / Q000187:drug effects; D004285:Dogs; D005260:Female; D007275:Injections, Intravenous; D008297:Male; D015425:Myocardial Reperfusion / Q000009:adverse effects*; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology*; D011292:Premedication; D013997:Time Factors; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D009292:Narcotic Antagonists; D009271:Naltrexone; C038981:nalmefene